Method and apparatus for cerebral embolic protection

ABSTRACT

An aortic shunt apparatus and methods for cerebral embolic protection are described for isolating the aortic arch vessels from the aortic lumen, for selectively perfusing the arch vessels with a fluid and for redirecting blood flow within the aortic lumen and any potential embolic materials carried in the blood through a shunt past the isolated arch vessels. The perfusion shunt apparatus may be mounted on a catheter or cannula for percutaneous introduction or for direct insertion into the aorta. The perfusion shunt apparatus has application for protecting a patient from embolic stroke and hypoperfusion during cardiopulmonary bypass or cardiac surgery and also for selectively perfusing the cerebrovascular circulation with oxygenated blood or with neuroprotective fluids in the presence of risk factors, such as head trauma or cardiac insufficiency. The perfusion shunt apparatus will also find application for selective perfusion of other organ systems within the body.

CROSS REFERENCE TO OTHER PATENT APPLICATIONS

[0001] This application is a continuation of application Ser. No.09/532,660, filed Mar. 20, 2000, now U.S, Pat. No. 6,254,563, which is acontinuation of application Ser. No. 09/212,580, filed Dec. 14, 1998,now U.S. Pat. No. 6,139,517, which claims the benefit of U.S.Provisional application Ser. No. 60/069,470, filed Dec. 15, 1997, whichare hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to an aortic shunt apparatus andmethods for cerebral embolic protection by isolating the aortic archvessels from the aortic lumen, selectively perfusing the arch vesselswith a fluid and directing blood flow within the aortic lumen and anypotential embolic materials carried in the blood through a shunt pastthe isolated arch vessels.

[0003] The perfusion shunt apparatus of the present invention may bemounted on a catheter or cannula for percutaneous introduction or fordirect insertion into a circulatory vessel, such as the aorta. Theperfusion shunt apparatus has application for protecting a patient fromembolic stroke or hypoperfusion during cardiopulmonary bypass or cardiacsurgery and also for selectively perfusing the cerebrovascularcirculation with oxygenated blood or with neuroprotective fluids in thepresence of risk factors, such as head trauma or cardiac insufficiency.The perfusion shunt apparatus will also find application for selectiveperfusion of other organ systems within the body.

BACKGROUND OF THE INVENTION

[0004] Over the past decades tremendous advances have been made in thearea of heart surgery, including such life saving surgical procedures ascoronary artery bypass grafting (CABG) and cardiac valve repair orreplacement surgery. Cardiopulmonary bypass (CPB) is an importantenabling technology that has helped to make these advances possible.Recently, however, there has been a growing awareness within the medicalcommunity and among the patient population of the potential sequelae oradverse affects of heart surgery and of cardiopulmonary bypass. Chiefamong these concerns is the potential for stroke or neurologic deficitassociated with heart surgery and with cardiopulmonary bypass. One ofthe likely causes of stroke and of neurologic deficit is the release ofemboli into the blood stream during heart surgery. Potential embolicmaterials include atherosclerotic plaques or calcific plaques fromwithin the ascending aorta or cardiac valves and thrombus or clots fromwithin the chambers of the heart. These potential emboli may bedislodged during surgical manipulation of the heart and the ascendingaorta or due to high velocity jetting (sometimes called the“sandblasting effect”) from the aortic perfusion cannula. Air thatenters the heart chambers or the blood stream during surgery throughopen incisions or through the aortic perfusion cannula is another sourceof potential emboli. Emboli that lodge in the brain may cause a strokeor other neurologic deficit. Clinical studies have shown a correlationbetween the number and size of emboli passing through the carotidarteries and the frequency and severity of neurologic damage. At leastone study has found that frank strokes seem to be associated withmacroemboli larger than approximately 100 micrometers in size, whereasmore subtle neurologic deficits seem to be associated with multiplemicroemboli smaller than approximately 100 micrometers in size. In orderto improve the outcome of cardiac surgery and to avoid adverseneurological effects it would be very beneficial to eliminate or reducethe potential of such cerebral embolic events.

[0005] Several medical journal articles have been published relating tocerebral embolization and adverse cerebral outcomes associated withcardiac surgery, e.g.: Determination or Size of Aortic Emboli andEmbolic Load During Coronary Artery Bypass Grafting; Barbut et al.; AnnThorac Surg 1997; 63; 1262-7; Aortic Atheromatosis and Risks of CerebralEmbolization; Barbut et al.; J Card & Vasc Anesth, Vol 10, No 1, 1996;pp 24-30; Aortic Atheroma is Related to Outcome but not Numbers ofEmboli During Coronary Bypass; Barbut et al.; Ann Thorac Surg 1997; 64;454-9; Adverse Cerebral Outcomes After Coronary Artery Bypass Surgery;Roach et al.; New England J of Med, Vol 335, No 25, 1996; pp 1857-1863;Signs of Brain Cell Injury During Open Heart Operations; Past andPresent; .ANG.berg; Ann Thorac Surg 1995; 59; 1312-5; The Role of CPBManagement in Neurobehavioral Outcomes After Cardiac Surgery; Murkin;Ann Thorac Surg 1995; 59; 1308-11; Risk Factors for Cerebral Injury andCardiac Surgery; Mills; Ann Thorac Surg 1995; 59; 1296-9; BrainMicroemboli Associated with Cardiopulmonary Bypass; A Histologic andMagnetic Resonance Imaging Study; Moody et al.; Ann Thorac Surg 1995;59; 1304-7; CNS Dysfunction After Cardiac Surgery; Defining the Problem;Murkin; Ann Thorac Surg 1995; 59; 1287+; Statement of Consensus onAssessment of Neurobehavioral Outcomes After Cardiac Surgery; Murkin etal.; Ann Thorac Surg 1995; 59; 1289-95; Heart-Brain Interactions;Neurocardiology Comes of Age; Sherman et al.; Mayo Clin Proc 62:1158-1160, 1987; Cerebral Hemodynamics After Low-Flow Versus No-FlowProcedures; van der Linden; Ann Thorac Surg 1995; 59; 1321-5; Predictorsof Cognitive Decline After Cardiac Operation; Newman et al.; Ann ThoracSurg 1995; 59; 1326-30; Cardiopulmonary Bypass; Perioperative CerebralBlood Flow and Postoperative Cognitive Deficit; Venn et al.; Ann ThoracSurg 1995; 59; 1331-5; Long-Term Neurologic Outcome After CardiacOperations; Sotaniemi; Ann Thorac Surg 1995; 59; 1336-9; Macroemboli andMicroemboli During Cardiopulmonary Bypass; Blauth; Ann Thorac Surg 1995;59; 1300-3.

[0006] Commonly owned, co-pending U.S. provision application No.60/060,117, and corresponding U.S. patent application Ser. No.09/158,405, which are hereby incorporated by reference, describe anaortic perfusion filter catheter for prevention of cerebral embolizationand embolic stroke during cardiopulmonary bypass or cardiac surgery. Thepatent literature also includes several other references relating tovascular filter devices for reducing or eliminating the potential ofembolization. These and all other patents and patent applicationsreferred to herein are hereby incorporated by reference in theirentirety. The following U.S. patents relates to vena cava filters; U.S.Pat. Nos. 5,549,626, 5,415,630, 5,152,777, 5,375,612, 4,793,348,4,817,600, 4,969,891, 5,059,205, 5,324,304, 5,108,418, 4,494,531. Thefollowing U.S. patents relate to vascular filter devices: U.S. Pat. Nos.5,496,277, 5,108,419, 4,723,549, 3,996,938. The following U.S. patentsrelate to aortic filters or aortic filters associated with atherectomydevices: U.S. Pat. Nos. 5,662,671, 5,769,816. The followinginternational patent applications relate to aortic filters or aorticfilters associated with atherectomy devices: WO 97/17100, WO 97/42879,WO 98/02084. The following international patent application relates to acarotid artery filter; WO 98/24377. The patent literature also includesthe following U.S. patents related to vascular shunts and associatedcatheters: U.S. Pat. Nos. 3,991,767, 5,129,883, 5,613,948. None of thesepatents related to vascular shunts provides an apparatus or methodsuitable for preventing of cerebral embolization and embolic stroke orfor performing selective perfusion of the aortic arch vessels to preventhypoperfusion during cardiopulmonary bypass or cardiac surgery.

[0007] While some of these previous devices and systems representadvances in the prevention of some causes of neurologic damage, therecontinues to be a tremendous need for improved apparatus and methods toprevent cerebral embolization, embolic stroke and cerebral hypoperfusionduring cardiopulmonary bypass and cardiac surgery. Similarly, therecontinues to be a tremendous need for apparatus and methods forselective perfusion of the cerebrovascular circulation with oxygenatedblood or with neuroprotective fluids in the presence of risk factors,such as head trauma or cardiac insufficiency and also for selectiveperfusion of other organ systems within the body.

SUMMARY OF THE INVENTION

[0008] In keeping with the foregoing discussion, the present inventiontakes the form of a perfusion shunt apparatus and methods for isolatingand selectively perfusing a segment of a patient's cardiovascular systemand for directing circulatory flow around the isolated segment. In aparticularly preferred embodiment of the invention, the perfusion shuntapparatus is configured as an aortic perfusion shunt apparatus fordeployment within a patient's aortic arch and methods are described forisolating the aortic arch vessels from the aortic lumen, for selectivelyperfusing the arch vessels with a fluid and for directing blood flowwithin the aortic lumen through a shunt conduit past the isolated archvessels. The perfusion shunt apparatus may be mounted on a catheter orcannula for percutaneous introduction via peripheral artery access orfor direct insertion into a circulatory vessel, such as the aorta. Theperfusion shunt apparatus protects the patient from cerebralembolization and embolic stroke during cardiopulmonary bypass or cardiacsurgery by directing potential emboli downstream from the aortic archvessels where they will be better tolerated by the body. The perfusionshunt apparatus further protects the patient from cerebral hypoperfusionby providing selective perfusion of the aortic arch vessels and thecerebrovascular circulation with oxygenated blood or withneuroprotective fluids. The perfusion shunt apparatus also findsapplication for selective perfusion of the cerebrovascular circulationin the presence of risk factors, such as head trauma or cardiacinsufficiency. The perfusion shunt apparatus will also find applicationfor selective perfusion of other organ systems within the body.

[0009] The perfusion shunt apparatus of the present invention includesan expandable shunt conduit with an upstream end, a downstream end andan internal lumen. The expandable shunt conduit is mounted on a catheteror cannula for percutaneous introduction via peripheral artery access orfor direct insertion into the aorta. The expandable shunt conduit is agenerally cylindrical tube of a flexible polymeric material or fabricthat may be impermeable or porous to blood. Located at the upstream endof the expandable shunt conduit is an upstream sealing member. Adownstream sealing member is located at the downstream end of theexpandable shunt conduit. Optionally, the expandable shunt conduit mayalso include a plurality of support members that bridge between theupstream sealing member and the downstream sealing member. Whendeployed, the upstream sealing member and the downstream sealing membersupport the expandable shunt conduit in an open, deployed configurationand create a seal between the expandable shunt conduit and the vesselwall. An annular chamber is created between the vessel wall and theshunt conduit. A perfusion lumen within the catheter shaft communicateswith the annular chamber external to the shunt conduit.

[0010] In one particularly preferred embodiment, the upstream sealingmember and the downstream sealing member are inflatable toroidal ballooncuffs, which are sealingly attached to the upstream end and thedownstream end of the expandable shunt conduit. In another embodiment,the upstream sealing member and the downstream sealing member are in theform of selectively deployable external flow valves. In yet anotherembodiment, the upstream sealing member and the downstream sealingmember include extendible and retractable elongated expansion members toexpand the upstream and downstream ends of the expandable shunt conduituntil they contact and create a seal against the inner surface of theaorta.

[0011] Optionally, an outer tube may be provided to cover the shuntconduit when it is in the collapsed state in order to create a smoothouter surface for insertion and withdrawal of the perfusion shuntapparatus and to prevent premature deployment of the shunt conduit.Optionally, each embodiment of the perfusion shunt apparatus may alsoinclude an occlusion device, such as an inflatable balloon, toselectively occlude and seal the lumen of the expandable shunt conduit.Each embodiment of the perfusion shunt apparatus may also include anembolic filter for filtering potential emboli from the blood passingthrough the internal lumen of the expandable shunt conduit. Eachembodiment of the perfusion shunt apparatus may include one or moreradiopaque markers, sonoreflective markers or light emitting devices toenhance imaging of the apparatus using fluoroscopy, ultrasonic imagingor aortic transillumination.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIGS. 1-3 show a perfusion shunt apparatus according to thepresent invention configured for retrograde deployment in a patient'saortic arch via a peripheral arterial access point. FIG. 1 is a cutawayperspective view of the perfusion shunt apparatus deployed within theaortic arch via femoral artery access. FIG. 2 is a cross section of theperfusion shunt apparatus taken along line 2-2 in FIG. 1. FIG. 3 showsthe apparatus with the shunt in a collapsed state for insertion orwithdrawal of the device from the patient.

[0013]FIG. 4 shows an alternate embodiment of the perfusion shuntapparatus using external flow control valves as sealing members.

[0014]FIGS. 5 and 6 show an aortic perfusion shunt apparatus configuredfor retrograde deployment via subclavian artery access. FIG. 5 is acutaway perspective view of the perfusion shunt apparatus deployedwithin the aorta. FIG. 6 shows the apparatus with the perfusion shuntconduit in a collapsed state for insertion or withdrawal of the devicefrom the patient.

[0015]FIGS. 7 and 8 show an aortic perfusion shunt apparatus configuredfor antegrade deployment via direct aortic insertion. FIG. 7 is acutaway perspective view of the perfusion shunt apparatus deployedwithin the aorta. FIG. 8 shows the apparatus with the perfusion shunt ina collapsed state for insertion or withdrawal of the device from theaorta.

[0016]FIGS. 9a-9 b and 10 a-10 b shows an embodiment of an aorticperfusion shunt apparatus with an aortic occlusion mechanism at theupstream end of the shunt conduit.

[0017]FIGS. 11a-11 b and 12 a-12 b show an alternate embodiment of anaortic perfusion shunt apparatus with an aortic occlusion mechanism atthe upstream end of the shunt conduit.

[0018]FIG. 13 shows an alternate construction of an aortic perfusionshunt apparatus according to the present invention.

[0019]FIG. 14a is an end view of the aortic perfusion shunt apparatus ofFIG. 13.

[0020]FIG. 14b is a cross section of the aortic perfusion shuntapparatus of FIG. 13.

[0021]FIG. 15 shows another alternate construction of an aorticperfusion shunt apparatus according to the present invention.

[0022]FIG. 16 is a cross section of the aortic perfusion shunt apparatusof FIG. 15.

[0023]FIG. 17 shows an aortic perfusion filter shunt apparatus accordingto the present invention.

[0024]FIG. 18 shows a combined aortic perfusion shunt apparatus with anembolic filter mechanism positioned at the downstream end of the shuntconduit.

[0025]FIG. 19 shows an alternate embodiment of an aortic perfusion shuntapparatus combined with an embolic filter mechanism positioned withinthe shunt conduit.

[0026]FIGS. 20 and 21 show an aortic perfusion shunt apparatusconfigured for retrograde deployment via femoral artery access andhaving upstream and downstream sealing members operated by extendibleand retractable elongated expansion members. FIG. 20 is a cutawayperspective view of the perfusion shunt apparatus deployed within theaorta. FIG. 21 shows the apparatus with the perfusion shunt conduit in acollapsed state for insertion or withdrawal of the device from thepatient.

DETAILED DESCRIPTION OF THE INVENTION

[0027] FIGS. 1-3 show a perfusion shunt apparatus 100 according to thepresent invention configured for retrograde deployment in a patient'saortic arch via a peripheral arterial access point. FIG. 1 is a cutawayperspective view of the perfusion shunt apparatus 100 deployed withinthe aortic arch via femoral artery access. FIG. 2 is a cross section ofthe perfusion shunt apparatus 100 taken along line 2-2 in FIG. 1. FIG. 3shows the distal end of the apparatus with the shunt conduit 102 in acollapsed state for insertion or withdrawal of the device from thepatient.

[0028] Referring now to FIG. 1, the perfusion shunt apparatus 100 isshown in an expanded or deployed state within a patient's aortic arch.The perfusion shunt apparatus 100 includes an expandable shunt conduit102, which has an upstream end 104, a downstream end 106 and an internallumen 112. Preferably, the expandable shunt conduit 102 is constructedas a generally cylindrical tube of a flexible polymeric material orfabric that is substantially impermeable to blood or fluid flow.Suitable materials for the expandable shunt conduit 102 include, but arenot limited to, polyvinylchloride, polyurethane, polyethylene,polypropylene, polyamides (nylons), polyesters and alloys of copolymersthereof, as well as knitted, woven or nonwoven fabrics. Located at theupstream end 104 of the expandable shunt conduit 102 is an upstreamshunt conduit support and sealing member 108. A downstream shunt conduitsupport and sealing member 110 is located at the downstream end 106 ofthe expandable shunt conduit 102. When deployed, the upstream sealingmember 108 and the downstream sealing member 110 support the expandableshunt conduit 102 in an open, deployed configuration and create a sealbetween the expandable shunt conduit 102 and the vessel wall, as shownin FIG. 1. An annular chamber 130 is thus created between the vesselwall and the shunt conduit 102. The annular chamber 130 is delimited onthe upstream end by the upstream sealing member 108 and on thedownstream end by the downstream sealing member 110 and is isolated fromthe internal lumen 112 by the cylindrical wall of the shunt conduit 102.In one particularly preferred embodiment, the upstream shunt conduitsupport and sealing member 108 and the downstream shunt conduit supportand sealing member 110 are configured as inflatable annular ballooncuffs, which are sealingly attached to the upstream end 104 and thedownstream end 106 of the expandable shunt conduit 102, respectively.Suitable materials for the inflatable annular balloon cuffs 108, 110include flexible polymers and elastomers, which include, but are notlimited to, polyvinylchloride, polyurethane, polyethylene,polypropylene, polyamides (nylons), polyesters, latex, silicone, andalloys, copolymers and reinforced composites thereof.

[0029] Optionally, the expandable shunt conduit 102 may also include aplurality of support members 136, which bridge between the upstreamsealing member 108 and the downstream sealing member 110. The supportmembers 136 strengthen the expandable shunt conduit 102 and help to holdthe internal lumen 112 open when the perfusion shunt apparatus 100 isdeployed. The support members 136 may be made of a semi-rigid, resilientwire or polymer material joined to or formed integrally with the wall ofthe shunt conduit 102. The support members 136 may be longitudinallyoriented with respect to the shunt conduit 102, as shown, or they may beconfigured as one or more circumferential hoops or helical supportmembers. The expandable shunt conduit 102 and the support members 136may be made in a straight, but somewhat flexible, configuration so thatthey conform naturally to the internal curvature of the patient's aorticarch when deployed. Alternatively, the expandable shunt conduit 102 andthe support members 136 may be preshaped with a curve to match theinternal curvature of the patient's aortic arch.

[0030] Preferably, the expandable shunt conduit 102 between the upstreammember 108 and the downstream sealing member 110 will have a lengthsufficient to bridge across the target branch vessels without occludingthem. In various embodiments configured for different clinicalapplications, the expandable shunt conduit 102 is preferably from 1 cmto 40 cm in length, more preferably from 5 cm to 15 cm in length. In oneparticularly preferred embodiment configured for perfusing the aorticarch vessels in adult human patients, the expandable shunt conduit 102is preferably approximately 8 cm to 12 cm in length. Likewise, thediameter of the expandable shunt conduit 102 is also adaptable for avariety of different clinical applications. The expandable shunt conduit102 should have a large enough diameter, when expanded, to allowsufficient blood flow through the expandable shunt conduit 102 toadequately perfuse the organs and tissues downstream of the deployedperfusion shunt apparatus 100. Preferably, the expandable shunt conduit102 is of a diameter slightly smaller than the host vessel into which itis intended to be introduced so that the wall of the expandable shuntconduit 102 is separated from the vessel wall creating an annularchamber 130 between the upstream sealing member 108 and the downstreamsealing member 110, as described above. This arrangement also preventsthe wall of the expandable shunt conduit 102 from occluding orrestricting flow of perfusate into the target branch vessels. In variousembodiments configured for different clinical applications, theexpandable shunt conduit 102 is preferably from 0.2 cm to 10 cm indiameter, more preferably from 1 cm to 5 cm in diameter. For deploymentin the aortic arch and perfusing the aortic arch vessels in adult humanpatients, the expandable shunt conduit 102 is preferably approximately1.0 cm to 2.5 cm in diameter. With these dimensions, the internal lumen112 of the expandable shunt conduit 102 will be capable of deliveringapproximately 2 to 4 liters of oxygenated blood per minute from theheart, which are necessary to adequately perfuse the organs and tissuesdownstream of the aortic arch. When deployed, the upstream sealingmember 108 and the downstream sealing member 110 preferably have aninner diameter approximately equal to the diameter of the expandableshunt conduit 102 and an outer diameter sufficient to seal against theinterior wall of the host vessel. In various embodiments configured fordifferent clinical applications, the upstream sealing member 108 and thedownstream sealing member 110 preferably have an outer diameter of 0.3cm to 15 cm, more preferably 1 cm to 7 cm. For deployment in the aorticarch in adult human patients, the upstream sealing member 108 and thedownstream sealing member 110 preferably have an outer diameter ofapproximately 1.5 cm to 3.5 cm.

[0031] Preferably, the expandable shunt conduit 102 is mounted on anelongated catheter shaft or cannula 102 for introduction into thepatient's circulatory system. In this exemplary embodiment of theperfusion shunt apparatus 100, the elongated catheter shaft 120 isconfigured for retrograde deployment of the expandable shunt conduit 102in a patient's aortic arch via a peripheral arterial access point, suchas the femoral artery. The elongated catheter shaft 120 should have alength sufficient to reach from the arterial access point where it isinserted into the patient to the aortic arch. For femoral arterydeployment, the elongated catheter shaft 120 preferably has a lengthfrom approximately 60 to 120 cm, more preferably 70 to 90 cm. Theelongated catheter shaft 120 is preferably extruded of a flexiblethermoplastic material or a thermoplastic elastomer. Suitable materialsfor the elongated catheter shaft 120 include, but are not limited to,polyvinylchloride, polyurethane, polyethylene, polypropylene, polyamides(nylons), polyesters, and alloys or copolymers thereof, as well asbraided, coiled or counterwound wire or filament reinforced composites.Optionally, the distal end of the catheter shaft 120 may be preshapedwith a curve to match the internal curvature of the patient's aorticarch.

[0032] As seen in the cross section of the apparatus in FIG. 2, theelongated catheter shaft 120 has a perfusion lumen 122, a firstinflation lumen 124 and a second inflation lumen 126. The catheter shaft120 has one or more perfusion ports 118 that connect the perfusion lumen122 with the annular chamber 130 on the exterior of the shunt conduit102 between the upstream sealing member 108 and the downstream sealingmember 110. The proximal end 128 of the elongated catheter shaft 120 isadapted for connecting the perfusion lumen 122 to a cardiopulmonarybypass pump or other source of oxygenated blood or other fluid usingstandard barb connectors or other connectors, such as a standard luerfitting (not shown). The perfusion lumen 122 should be configured toallow sufficient fluid flow to preserve organ and tissue function of theorgans and tissues supplied by the target branch vessels. For cerebralperfusion, the perfusion lumen 122 should be configured to allowsufficient fluid flow to preserve organ function of the brain and othertissues supplied by the arch vessels. For normothermic perfusion withoxygenated blood, the perfusion lumen 122 should have sufficientcross-sectional area to allow 0.5 to 1.5 liters per minute, and morepreferably 0.75 to 1.0 liters per minute, of blood flow withoutsignificant hemolysis or other damage to the blood. For hypothermicperfusion with cooled oxygenated blood, the flow rate can be reduced to0.25 to 0.75 liters per minute, permitting a reduction in thecross-sectional area of the perfusion lumen 122. For perfusion withblood substitutes, such as perfluorocarbons, or with neuroplegicsolutions, the cross-sectional area of the perfusion lumen 122 should bedesigned to allow sufficient flow rate to preserve organ function giventhe viscosity, pressure susceptibility and the oxygen and metabolitetransport capabilities of the chosen perfusate fluid.

[0033] Optionally, the perfusion shunt apparatus 100 may be configuredfor introduction over a guidewire. For example, the perfusion lumen 122of the elongated catheter shaft 120 may be adapted for accepting aguidewire. The perfusion lumen 122 may be provided with a distal openingat the distal end of the elongated catheter shaft 120 for passing aguidewire, such as an 0.035 or 0.038 inch diameter guidewire.Optionally, a valve, such as the catheter valve described in U.S. Pat.No. 5,085,635, which is hereby incorporated by reference, may beincluded at the distal end of the perfusion lumen 122 to preventperfusate from passing through the distal opening during perfusion.Alternatively, the elongated catheter shaft 120 may include an additionlumen (not shown) for introducing the perfusion shunt apparatus 100 overa guidewire.

[0034] In various embodiments of the perfusion shunt apparatus 100configured for different clinical applications, the elongated cathetershaft 120 preferably has an external diameter from 3 to 24 French size(1 to 8 mm diameter), more preferably from 8 to 16 French size (2.7 to5.3 mm diameter). In one particularly preferred embodiment configuredfor perfusing the aortic arch vessels with normothermic blood in adulthuman patients, the elongated catheter shaft 120 preferably has a lengthof approximately 70 to 90 cm and an external diameter from approximately10 to 14 French size (3.3 to 4.6 mm diameter), which allows a flow rateof approximately 0.75 to 1.0 liters per minute. In another preferredembodiment configured for perfusing the aortic arch vessels withhypothermic blood in adult human patients, the elongated catheter shaft120 preferably has a length of approximately 70 to 90 cm and an externaldiameter from approximately 8 to 12 French size (2.6 to 4.0 mmdiameter), which allows a flow rate of approximately 0.25 to 0.75 litersper minute.

[0035] Preferably, the perfusion shunt apparatus 100 includes one ormore markers, which may include radiopaque markers and/or sonoreflectivemarkers, to enhance imaging of the perfusion shunt apparatus 100 usingfluoroscopy or ultrasound, such as transesophageal echography (TEE). Byway of example, FIGS. 1 and 3 show a perfusion shunt apparatus 100having a first, upstream radiopaque and/or sonoreflective marker ring140 on the catheter shaft 120 just proximal to the upstream sealingmember 108 and a second, downstream radiopaque and/or sonoreflectivemarker ring 142 on the catheter shaft 120 just distal to the downstreamsealing member 110. Alternatively or additionally, radiopaque markersand/or sonoreflective markers may be placed on the sealing members 108,110 and/or the shunt conduit 102 to show the position and/or thedeployment state of the perfusion shunt apparatus 100.

[0036] A first inflation port 114 connects the first inflation lumen 124with the interior of the inflatable annular balloon cuff that forms theupstream sealing member 108. The proximal end of the first inflationlumen 124 is connected to a first luer fitting 132 or other suitableinflation connector. A second inflation port 114 connects the secondinflation lumen 126 with the interior of the inflatable annular ballooncuff of the downstream sealing member 110. The proximal end of thesecond inflation lumen 126 is connected to a second luer fitting 134 orother suitable inflation connector. This configuration allows individualinflation and deflation control of the upstream sealing member 108 andthe downstream sealing member 110. In an alternate configuration of theperfusion shunt apparatus 100, the elongated catheter shaft 120 may bemade with a single inflation lumen connected to both the first inflationport 114 and the second inflation port 114 and connected at the proximalend to a single luer fitting. In this alternate configuration, theupstream sealing member 108 and the downstream sealing member 110 wouldbe simultaneously inflated and deflated through the single inflationlumen. Such a configuration could be used to reduce the overall diameterof the elongated catheter shaft 120.

[0037] Referring now to FIG. 3, the perfusion shunt apparatus 100 isshown in an undeployed or collapsed state for insertion or withdrawal ofthe device from the patient. To place the perfusion shunt apparatus 100in the collapsed state, the upstream sealing member 108 and thedownstream sealing member 110′ are deflated and the shunt conduit 102′is wrapped or folded around the catheter shaft 120 to reduce its overalldiameter. Optionally, an outer tube 138 may be provided to cover theshunt conduit 102 when it is in the collapsed state in order to create asmooth outer surface for insertion and withdrawal of the perfusion shuntapparatus 100 and to prevent premature deployment of the shunt conduit102.

[0038] The perfusion shunt apparatus 100 is prepared for use by foldingor compressing the shunt conduit 102′ into a collapsed state within theouter tube 138, as shown in FIG. 3. The distal end of the perfusionshunt apparatus 100 is then inserted into the aorta in a retrogradefashion. Preferably, this is done through a peripheral arterial access,such as the femoral artery or subclavian artery, using the Seldingertechnique or an arterial cutdown. Alternatively, the perfusion shuntapparatus 100 may be introduced directly through an incision into thedescending aorta after the aorta has been surgically exposed. Theperfusion shunt apparatus 100 is advanced up the descending aorta andacross the aortic arch while in the collapsed state. The position of theperfusion shunt apparatus 100 may be monitored using fluoroscopy orultrasound, such as transesophageal echography (TEE), with the help ofthe radiopaque markers and/or sonoreflective markers 140, 142 on thecatheter shaft 120. When the upstream marker ring 140 is positioned inthe ascending aorta between the aortic valve and the brachiocephalicartery and the downstream marker ring 142 is positioned downstream ofthe left subclavian artery, the outer tube 124 is withdrawn and theshunt conduit 102 is expanded by inflating the upstream sealing member108 and the downstream sealing member 110, as shown in FIG. 1. Toencourage the upstream sealing member 108 and the downstream sealingmember 110 to seal with the inner surface of the aorta, they may be madewith differential wall compliance that encourages the toroidal balloonsto expand outward, away from the expandable shunt conduit 102. Forexample, the upstream sealing member 108 and the downstream sealingmember 110 may be made with a thicker balloon wall 109 near the innersurface of the toroidal balloon and a thinner balloon wall 111 near theouter surface of the toroidal balloon, as indicated in FIG. 2.Differential wall compliance can also be accomplished by combiningdifferent balloon materials of varying elasticity. The annular chamber130 surrounding the shunt conduit 102 created by inflation of theupstream sealing member 108 and the downstream sealing member 110 isfluidly connected to the arch vessels and is isolated from the lumen ofthe aorta. Once the perfusion shunt apparatus 100 is deployed,oxygenated blood or another chosen perfusate may be infused through theperfusion lumen 122 to selectively perfuse the arch vessels that deliverblood to the brain and the upper extremities.

[0039] If the perfusion shunt apparatus 100 is to be used in conjunctionwith cardiopulmonary bypass, an arterial return cannula 146 may beplaced in the ascending aorta upstream of the shunt conduit 102 usingknown methods. Blood flow the aortic lumen from the beating heart and/orfrom the arterial return cannula 146 is shunted past the arch vesselsthrough the internal lumen 112 of the shunt conduit 102. If desired, astandard cross clamp and a cardioplegia needle or an intra-aorticocclusion catheter, such as described in U.S. Pat. Nos. 5,308,320 and5,383,854, by Peter Safar, S. William Stezoski, and Miroslav Klain,which are hereby incorporated by reference may be applied upstream ofthe arterial cannula 146 for isolating the coronary arteries andinducing cardioplegic arrest. After use, the shunt conduit 102 isreturned to the collapsed position by deflating the upstream sealingmember 108 and the downstream sealing member 110 and advancing the outertube 138 distally over the shunt conduit 102, then the apparatus 100 iswithdrawn from the patient.

[0040] Selective perfusion of the arch vessels provides protection fromembolization or hypoperfusion of the brain. Any potential emboli fromthe cardiopulmonary bypass circuit or from surgical manipulation of theheart or the aorta are prevented from entering the neurovascular throughthe arch vessels. After use, the perfusion shunt assembly 102 isreturned to the collapsed position and the catheter 100 is withdrawnfrom the patient.

[0041] In an alternate method for use with this and other embodiments ofthe perfusion shunt apparatus described herein, the perfusion shuntapparatus 100 may be deployed by inflating the upstream sealing member108 only to expand the shunt conduit 102 and leaving the downstreamsealing member 110 uninflated. Aortic blood flow from the heart or froman arterial return cannula 146 will hold the shunt conduit 102 in theopen position. Potential emboli are prevented from entering the archvessels and the cerebral circulation by pumping perfusate through theperfusion lumen 122 at a sufficient rate to create a pressure gradientthat prevents blood flowing through the shunt conduit 102 from enteringthe annular chamber 130 surrounding the shunt conduit 102. When usingthis alternate method, the perfusion shunt apparatus 100 may besimplified by eliminating the downstream sealing member 110 from theshunt conduit 102.

[0042] In an alternate embodiment of the perfusion shunt apparatus 150,shown deployed within a patient's aortic arch in FIG. 4, the upstreamsealing member 152 and the downstream sealing member 154 may take theform of external flow control valves, as described in commonly owned,copending patent application Ser. No. 08/665,635, 08/664,361, now U.S.Pat. No. 5,827,237, and Ser. No. 08/664,360, now U.S. Pat. No.5,833,671, which are hereby incorporated by reference. In this alternateembodiment, the upstream sealing member 152 would preferably be in theform of an antegrade, peripheral flow valve and the downstream sealingmember 154 would preferably be in the form of a retrograde, peripheralflow vale. In such a configuration, positive perfusion pressure withinthe annular chamber 156 surrounding the shunt conduit 160 would tend toseal the upstream sealing member 152 and the downstream sealing member154 against the vessel wall. However, in the event that the perfusionpressure within the annular chamber 156 dropped below aortic pressure,the upstream sealing member 152 would open so that aortic blood flowcould augment the cerebral blood flow delivered through the perfusionlumen 162. Alternatively or in addition to this passive valve action,the upstream sealing member 152 and the downstream sealing member 154may be actively deployed by one or more actuation wires 158 extendingthrough the elongated shaft 166 of apparatus. The actuation wires 158would be attached at their distal ends to one or more of the valveleaflets of the upstream sealing member 152 and the downstream sealingmember 154 and at their proximal ends to one or more slide buttons 164or other actuation means for independent or simultaneous deployment.

[0043] The foregoing examples of the perfusion shunt apparatus of thepresent invention show retrograde deployment of the device within theaorta via femoral artery access. Each of the described embodiments ofthe perfusion shunt apparatus can also be adapted for retrogradedeployment via subclavian artery access or for antegrade or retrogradedeployment via direct aortic puncture.

[0044] Retrograde deployment of the perfusion shunt apparatus 100 viadirect aortic puncture is quite similar to introduction via femoralartery access, except that the perfusion shunt apparatus 100 isintroduced directly into the descending aorta after it has beensurgically exposed, for example during open-chest or minimally invasivecardiac surgery. Because of the direct aortic insertion, the length andthe diameter of the catheter shaft 120 may be significantly reduced.

[0045]FIGS. 5 and 6 show an aortic perfusion shunt apparatus 170configured for retrograde deployment via subclavian artery access. FIG.5 is a cutaway perspective view of the perfusion shunt apparatus 170deployed within the aorta. FIG. 6 shows the distal end of the apparatus170 with the perfusion shunt in a collapsed state for insertion orwithdrawal of the device from the patient. Because it is intended forsubclavian artery access, the perfusion shunt apparatus 170 has acatheter shaft 172 with a length of approximately 45 to 90 cm. Becauseof the shorter length, as compared to the femoral version of thecatheter, the outside diameter of the catheter shaft 172 can be reducedto 6 to 12 French size (2 to 4 mm outside diameter) for delivering the0.25 to 1.5 liters per minute of oxygenated blood needed to perfuse thearch vessels to preserve organ function. The reduced diameter of thecatheter shaft 172 is especially advantageous for subclavian arterydelivery of the perfusion shunt apparatus 170. To further reduce thesize of the catheter system for subclavian or femoral artery delivery,the outer tube 174 may be adapted for use as an introducer sheath by theaddition of an optional hemostasis valve 176 at the proximal end of theouter tube 174. This eliminates the need for a separate introducersheath for introducing the perfusion shunt apparatus 170 into thecirculatory system.

[0046] In use, the perfusion shunt apparatus 170 is introduced into thesubclavian artery, using the Seldinger technique or an arterial cutdown,with the perfusion shunt conduit 178′ in a collapsed state within theouter tube 176, as shown in FIG. 6. The perfusion shunt apparatus 170 isadvanced across the aortic arch while in the collapsed state. Theposition of the perfusion shunt apparatus 170 may be monitored usingfluoroscopy or ultrasound, such as transesophageal echography (TEE) withthe help of upstream and downstream radiopaque markers and/orsonoreflective markers 180, 182, located on the catheter shaft 172and/or the perfusion shunt conduit 178. When the upstream marker 180 ispositioned in the ascending aorta between the aortic valve and thebrachiocephalic artery and the downstream marker 182 is positioned atthe ostium of the left subclavian artery, the outer tube 174 iswithdrawn and the shunt conduit 102 is expanded by inflating theupstream sealing member 184 and the downstream sealing member 186, asshown in FIG. 5. In a preferred embodiment of the apparatus, thecatheter shaft 172 has a preformed bend 188 at the point where it passesthrough the downstream sealing member 186 and where it makes thetransition from the left subclavian artery into the aortic arch toassist seating the apparatus 170 in the correct position. The downstreamsealing member 186 is configured so that when it is inflated it alsooccludes the left subclavian artery. The annular chamber 190 surroundingthe shunt conduit 178 created by inflation of the upstream sealingmember 184 and the downstream sealing member 186 is fluidly connected tothe arch vessels and is isolated from the lumen of the aorta.

[0047] Once the perfusion shunt apparatus 170 is deployed, oxygenatedblood or another chosen perfusate may be infused through a firstperfusion lumen 192 and out through one or more perfusion ports 194 toselectively perfuse the arch vessels that deliver blood to the brain andthe upper extremities. Because the left subclavian artery is occluded bythe downstream sealing member 186 when it is inflated, a secondperfusion lumen 196 is provided in the catheter shaft 172 to perfuse theleft upper extremity through a perfusion port 198 located on thecatheter shaft 172 proximal to the downstream sealing member 186.Additionally or alternatively, the arch vessels may be perfused througha cannula placed in a branch of one of the arch vessels, such as thepatient's right subclavian artery. Such an arrangement would allow theperfusion lumen 192 to be reduced in size or even eliminated from theapparatus 170. Again, if the perfusion shunt apparatus 170 is to be usedin conjunction with cardiopulmonary bypass, an arterial return cannula146 may be placed in the ascending aorta upstream of the shunt conduit178 using known methods. Blood flow through the aortic lumen from thebeating heart and/or from the arterial return cannula 146 is shuntedpast the arch vessels through the internal lumen of the shunt conduit178. After use, the shunt conduit 178 is returned to the collapsedposition by deflating the upstream sealing member 184 and the downstreamsealing member 186 and advancing the outer tube 176 distally over theshunt conduit 178, then the apparatus 170 is withdrawn from the patient.

[0048]FIGS. 7 and 8 show an aortic perfusion shunt apparatus 200configured for antegrade deployment via direct aortic insertion. FIG. 7is a cutaway perspective view of the perfusion shunt apparatus 200deployed with the perfusion shunt conduit 202 in an expanded statewithin the aorta. FIG. 8 shows the apparatus 200 with the perfusionshunt conduit 202′ in a collapsed state for insertion or withdrawal ofthe device from the aorta.

[0049] The perfusion shunt conduit 202 is mounted on an elongatedcatheter shaft 208. The perfusion shunt conduit 202 is similar to theembodiments previously described except that, because the aorticperfusion shunt apparatus 200 is introduced into the ascending aorta inthe antegrade direction, the upstream sealing member 206 is positionedproximally to the downstream sealing member 204 on the elongatedcatheter shaft 208. The elongated catheter shaft 208 has a perfusionlumen 214 which is fluidly connected to one or more perfusion ports 216located on the catheter shaft 208 between the upstream sealing member206 and the downstream sealing member 204. The proximal end of theelongated catheter shaft 208 is adapted for connecting the perfusionlumen 214 to a cardiopulmonary bypass pump or other source of oxygenatedblood or other fluid using standard barb connectors or other connectors.A first inflation lumen 218 fluidly connects a first luer fitting 220with a first inflation port 222 located on the interior of the upstreamsealing member 206. A second inflation lumen 224 fluidly connects asecond luer fitting 226 with a second inflation port 228 located on theinterior of the downstream sealing member 204. Optionally, the elongatedcatheter shaft 208 may also include a second perfusion lumen (notshown), which would be connected to one or more perfusion ports locatedupstream of the upstream sealing member 206.

[0050] The perfusion lumen 214 should be configured to allow sufficientfluid flow to preserve organ and tissue function of the organs andtissues supplied by the target branch vessels. Because the perfusionshunt apparatus 200 is introduced directly into the ascending aorta, theelongated catheter shaft 208 can be reduced to a length of approximately20 to 60 cm and an outside diameter of approximately 6 to 12 French size(2 to 4 mm outside diameter) for delivering the 0.25 to 1.5 liters perminute of oxygenated blood needed to perfuse the arch vessels topreserve organ function.

[0051] Preferably, the perfusion shunt apparatus 200 includes a first,upstream radiopaque and/or sonoreflective marker ring 210 on thecatheter shaft 208 just distal to the upstream sealing member 206 and asecond, downstream radiopaque and/or sonoreflective marker ring 212 onthe catheter shaft 208 just proximal to the downstream sealing member204. Visual markers may also be placed on the catheter shaft 208 toassist placement under direct or thoracoscopic visualization.

[0052] In use, a purse string suture is placed in the wall of theascending aorta and an aortotomy incision is made. The perfusion shuntapparatus 200 is introduced into the ascending aorta through theaortotomy incision, with the perfusion shunt conduit 202′, upstreamsealing member 206′ and the downstream sealing member 204′ in acollapsed state, as shown in FIG. 8. Optionally, the collapsed perfusionshunt conduit 202′ may be covered with an outer tube 230 to easeinsertion of the device and to prevent premature deployment. Theperfusion shunt apparatus 200 is advanced across the aortic arch in anantegrade fashion. The position of the perfusion shunt apparatus 200 maybe monitored using fluoroscopy or ultrasound, such as transesophagealechography (TEE). When the upstream marker 210 is positioned in theascending aorta between the aortic valve and the brachiocephalic arteryand the downstream marker 212 is positioned downstream of the leftsubclavian artery, the outer tube 230 is withdrawn and the shunt conduit202 is expanded by inflating the upstream sealing member 206 and thedownstream sealing member 204, as shown in FIG. 7. In one preferredembodiment, the catheter shaft 208 has a preformed bend 232 proximal tothe perfusion shunt conduit 202 where the catheter shaft 208 passesthrough the aortic wall to assist seating the apparatus 200 in thecorrect position. Once the perfusion shunt apparatus 200 is deployed,oxygenated blood or another chosen perfusate may be infused through aperfusion lumen 214 and out thorough the perfusion ports 216 toselectively perfuse the arch vessels. If the perfusion shunt apparatus200 is to be used in conjunction with cardiopulmonary bypass, anarterial return cannula (not shown) may be placed in the ascending aortaupstream of the shunt conduit 202 using known methods or the aorta maybe perfused through the optional second perfusion lumen discussed above.Blood flow through the aortic lumen from the beating heart and/or fromthe arterial return cannula is shunted past the arch vessels through theinternal lumen of the shunt conduit 202. For complete cardiopulmonarybypass with cardioplegic arrest, the perfusion shunt apparatus 200 maybe used in combination with a standard aortic cross clamp or with anintra aortic balloon clamp. After use, the shunt conduit 202 is returnedto the collapsed position by deflating the upstream sealing member 206and the downstream sealing member 204 and advancing the outer tube 230distally over the shunt conduit 202, then the apparatus 200 is withdrawnfrom the patient.

[0053]FIGS. 9a-9 b and 10 a-10 b show an embodiment of an aorticperfusion shunt apparatus 240 with an aortic occlusion mechanism at theupstream end of the expandable shunt conduit 242. FIG. 9a shows theaortic perfusion shunt apparatus 240 with the expandable shunt conduit242 deployed within a patient's aortic arch. FIG. 9b is a distal endview of the expandable shunt conduit 242 of the aortic perfusion shuntapparatus 240 of FIG. 9a. FIG. 10a shows the aortic perfusion shuntapparatus 240 of FIG. 9a with the aortic occlusion mechanism 244′activated to block flow through the expandable shunt conduit 242. FIG.10b is a distal end view of the expandable shunt conduit 242 andactivated aortic occlusion mechanism 244′ of FIG. 10a.

[0054] This embodiment of the aortic perfusion shunt apparatus 240 maybe adapted for retrograde deployment via peripheral arterial access, asshown, or it may be adapted for antegrade deployment via direct aorticinsertion. In most aspects, the aortic perfusion shunt apparatus 240 andthe expandable shunt conduit 242 are similar in construction to theembodiments previously described. However, the upstream sealing member244 is adapted so that it also serves as an aortic occlusion mechanism.The upstream sealing member 244 is expandable from a collapsed positionfor insertion to an expanded position for sealing between the expandableshunt conduit 242 and the aortic wall, as shown in FIGS. 9a and 9 b. Asshown in FIGS. 10a and 10 b, the upstream sealing member 244′ is furtherexpandable to an occluding position in which the inner diameter of thetoroidal upstream sealing member 244′ decreases to occlude the innerlumen 246 of the expandable shunt conduit 242. To encourage the upstreamsealing member 244′ to expand inward to occlude the inner lumen 246 ofthe expandable shunt conduit 242, the toroidal balloon 244 may be madewith differential wall compliance. For example, the toroidal upstreamsealing member 144 may be made with a thinner balloon wall 243 near theinner surface of the toroidal balloon and a thicker balloon wall 245near the outer surface of the toroidal balloon, as indicated in FIG.10b. Differential wall compliance can also be accomplished by combiningdifferent balloon materials of varying elasticity. This integral aorticocclusion mechanism obviates the need for a separate aortic cross clampor intra aortic balloon clamp when the aortic perfusion shunt apparatus240 is used for complete cardiopulmonary bypass with cardioplegicarrest. Preferably, the aortic perfusion shunt apparatus 240 alsoincludes a cardioplegia lumen 248, which extends from the distal end ofthe elongated catheter shaft 252 to a luer fitting 250 on the proximalend. The cardioplegia lumen 248 may also be used as a guidewire lumen toassist introduction of the device into the vasculature.

[0055] After the upstream sealing member 244′ has been inflated to itsoccluding position, cardioplegic solution may be infused through thecardioplegia lumen 248 into the aortic root and hence into the coronaryarteries to induce cardioplegic arrest. The arch vessels may beselectively perfused through the perfusion lumen 254, which connects toone or more perfusion ports 256 located on the exterior of the cathetershaft 252 between the upstream sealing member 244 and the downstreamsealing member 252. The descending aorta downstream of the perfusionshunt apparatus 240 may be perfused through a separate arterial cannula,which may be placed in the contralateral femoral artery or which may becoaxial to the elongated catheter shaft 252. Alternatively, theelongated catheter shaft 252 of the perfusion shunt apparatus 240 may beprovided with a second perfusion lumen (not shown) connecting toperfusion ports located downstream of the downstream sealing member 252.

[0056] The patient can be converted from cardioplegic arrest to abeating heart condition, while maintaining selective perfusion of thearch vessels, by partially deflating the upstream sealing member fromthe occluding position 244′ to the expanded position 244. This allowsoxygenated blood to flow retrograde through the inner lumen 246 of theexpandable shunt conduit 242 and into the coronary arteries to revivethe arrested heart. Once the heart has resumed beating, blood flow fromthe heart will flow antegrade through the expandable shunt conduit 242to the rest of the body. Selective perfusion of the arch vessels throughthe perfusion lumen 254 may be maintained as long as necessary. Afteruse, the shunt conduit 242 is returned to the collapsed position bydeflating the upstream sealing member 244 and the downstream sealingmember 252 and the apparatus 240 is withdrawn from the patient.

[0057]FIGS. 11a-11 b and 12 a-12 b show an alternate embodiment of anaortic perfusion shunt apparatus 260 with an aortic occlusion mechanism280 at the upstream end of the expandable shunt conduit 262. FIG. 11ashows the aortic perfusion shunt apparatus 260 with the expandable shuntconduit 262 deployed within a patient's aortic arch. FIG. 11b is adistal end view of the expandable shunt conduit 262 of the aorticperfusion shunt apparatus 260 of FIG. 11a. FIG. 12a shows the aorticperfusion shunt apparatus 260 of FIG. 11a with the aortic occlusionmechanism 280′ activated to block flow through the expandable shuntconduit 262. FIG. 12b is a distal end view of the expandable shuntconduit 262 and activated aortic occlusion mechanism 280′ of FIG. 12a.

[0058] Again, most aspects of the aortic perfusion shunt apparatus 260and the expandable shunt conduit 262 are similar in construction to theembodiments previously described. In addition, however, the aorticperfusion shunt apparatus 260 includes an occlusion member 280 withinthe inner lumen 266 of the expandable shunt conduit 262. In onepreferred embodiment, the occlusion member 280 is an expandable balloon,which may be generally spherical in shape and may be made of a flexiblepolymer or elastomer, such as polyvinylchloride, polyurethane,polyethylene, polypropylene, polyamides (nylons), polyester, latex,silicon, or alloys, copolymers and reinforced composites thereof. Theocclusion member 280 is fluidly connected by an inflation lumen 282 to aluer fitting 284 or other connector on the proximal end of the perfusionshunt apparatus 260. The occlusion member 280 is inflatable from acollapsed position 280, shown in FIG. 11b, to an occluding position280′, shown in FIG. 12b, to occlude the inner lumen 266 of theexpandable shunt conduit 262. Alternatively, the occlusion member 280may be a flap or valve, which is selectively actuatable to occlude theinner lumen 266 of the expandable shunt conduit 262. This integralaortic occlusion mechanism obviates the need for a separate aortic crossclamp or intra aortic balloon clamp when the aortic perfusion shuntapparatus 260 is used for complete cardiopulmonary bypass withcardioplegic arrest. Preferably, the aortic perfusion shunt apparatus260 also includes a cardioplegia lumen 268, which extends from thedistal end of the elongated catheter shaft 272 to a luer fitting 270 onthe proximal end. The cardioplegia lumen 268 may also be used as aguidewire lumen to assist introduction of the device into thevasculature.

[0059] After the occlusion member 280′ has been inflated to itsoccluding position, cardioplegic solution may be infused through thecardioplegia lumen 268 into the aortic root and hence into the coronaryarteries to induce cardioplegic arrest. The arch vessels may beselectively perfused through the perfusion lumen 274, which connects toone or more perfusion ports 276 located on the exterior of the cathetershaft 272 between the upstream sealing member 264 and the downstreamsealing member 272. The descending aorta downstream of the perfusionshunt apparatus 260 may be perfused through a separate arterial cannula,which may be placed in the contralateral femoral artery or which may becoaxial to the elongated catheter shaft 272. Alternatively, theelongated catheter shaft 272 of the perfusion shunt apparatus 260 may beprovided with a second perfusion lumen (not shown) connecting toperfusion ports located downstream of the downstream sealing member 272.

[0060] The patient can be converted from cardioplegic arrest to abeating heart condition, while maintaining selective perfusion of thearch vessels, by partially or completely deflating the occlusion member280 from the occluding position 280′ to the collapsed position 280. Thisallows oxygenated blood to flow retrograde through the inner lumen 266of the expandable shunt conduit 262 and into the coronary arteries torevive the arrested heart. Once the heart has resumed beating, bloodflow from the heart will flow antegrade through the expandable shuntconduit 262 to the rest of the body. Selective perfusion of the archvessels through the perfusion lumen 274 may be maintained as long asnecessary. After use, the shunt conduit 262 is returned to the collapsedposition by deflating the upstream sealing member 264 and the downstreamsealing member 272 and the apparatus 260 is withdrawn from the patient.

[0061]FIGS. 13, 14a and 14 b show an alternate construction of an aorticperfusion shunt apparatus 290 according to the present invention. FIG.13 shows the aortic perfusion shunt apparatus 290 deployed within apatient's aorta. FIG. 14a is an end view of the aortic perfusion shuntapparatus 290 of FIG. 13. FIG. 14b is a cross section of the aorticperfusion shunt apparatus 290 of FIG. 13. This alternate constructionmay be used with any of the embodiments of the perfusion shunt apparatusdescribed herein. In most respects, the aortic perfusion shunt apparatus290 and the expandable shunt conduit 292 are similar in construction tothe embodiments previously described. However, in this embodiment adistal portion of the elongated catheter shaft 294 passes through theinner lumen 296 of the expandable shunt conduit 292. One or moreperfusion ports connect to the catheter shaft 294 through the wall ofthe expandable shunt conduit 292. This construction of the aorticperfusion shunt apparatus 290 allows the expandable shunt conduit 292 tobe made in a larger diameter, more closely approximating the luminaldiameter of the host vessel, in this case the aortic arch. It alsoallows a clear unobstructed flow of perfusate around the exterior of theexpandable shunt conduit 292. This aspect may be important for otherclinical applications where the target branch vessels are distributedaround the host vessel rather than lined up along one side of the hostvessel, such as in the descending aorta.

[0062]FIGS. 15 and 16 show another alternate construction of an aorticperfusion shunt apparatus 300 according to the present invention. FIG.15 shows the aortic perfusion shunt apparatus 300 deployed within apatient's aorta. FIG. 16 is a cross section of the aortic perfusionshunt apparatus 300 of FIG. 15. Once again, this alternate constructionmay be used with any of the embodiments of the perfusion shunt apparatusdescribed herein. In most respects, the aortic perfusion shunt apparatus300 and the expandable shunt conduit 302 are similar in construction tothe embodiments previously described. However, in this embodiment theupstream sealing member 304 and the downstream sealing member 306 areeccentric toroidal balloon cuffs with the larger side of the eccentrictoroidal balloon cuffs positioned toward the arch vessels on thesuperior side of the aortic arch. This displaces the expandable shuntconduit 302 and the elongated catheter shaft 308 toward the inferiorside of the aortic arch and away from the arch vessels. The expandableshunt conduit 302 and the elongated catheter shaft 308 are thus lesslikely to interfere with blood flow into the arch vessels when theaortic perfusion shunt apparatus 300 is deployed.

[0063]FIG. 17 shows an aortic perfusion filter shunt apparatus 310according to the present invention. In most respects, the aorticperfusion shunt apparatus 310 and the expandable shunt conduit 312 aresimilar in construction to the embodiments previously described.However, in this embodiment, rather than being made of a relativelyimpermeable material, the expandable shunt conduit 312 is made of aporous filter mesh material. Optionally the downstream end of theexpandable shunt conduit 312 may have an end wall 318 of filter meshmaterial across the inner lumen 320 of the expandable shunt conduit 312,as well. The filter mesh material of the expandable shunt conduit 312may be a woven or knitted fabric, such as Dacron or nylon mesh, or otherfabrics, or it may be a nonwoven fabric, such as a spun bondedpolyolefin or expanded polytetrafluoroethylene or other nonwovenmaterial. Alternatively, the filter mesh material of the expandableshunt conduit 312 may be an open cell foam material. The filter meshmaterial of the expandable shunt conduit 312 must be nontoxic andhemocompatible, that is, non-thrombogenic and non-hemolytic. Preferably,the filter mesh material of the expandable shunt conduit 312 has a highpercentage of open space, with a uniform pore size. The pore size of thefilter mesh material can be chosen to capture macroemboli only or tocapture macroemboli and microemboli. In most cases the pore size of thefilter mesh material will preferably be in the range of 1-200micrometers. For capturing macroemboli only, the pore size of the filtermesh material will preferably be in the range of 50-200 micrometers,more preferably in the range of 80-100 micrometers. For capturingmacroemboli and microemboli, the pore size of the filter mesh materialwill preferably be in the range of 1-100 micrometers, more preferably inthe range of 5-20 micrometers. In other applications, such as fortreating thromboemolic disease, a larger pore size, e.g. up to 1000micrometers (1 mm) or larger, would also be useful. In some embodiments,a combination of filter materials having different pore sizes may beused. The expandable shunt conduit 312 and the end wall 318 may be madeof filter mesh materials having different pore sizes. For example, theexpandable shunt conduit 312 may be made with a very fine filter meshmaterial for capturing both macroemboli and microemboli, and the endwall 318 may be made of a coarser filter mesh material for capturingmacroemboli only.

[0064] When the aortic perfusion filter shunt apparatus 310 is deployedwithin the aortic arch, the filter mesh material of the expandable shuntconduit 312 will protect the arch vessels and prevent emboli fromentering the cerebral vasculature. Potential emboli that are stopped bythe filter mesh material of the expandable shunt conduit 312 will eitherpass through the inner lumen 320 of the expandable shunt conduit 312 andflow downstream where they will be better tolerated or they will bestopped by the filter mesh material of the end wall 318. Undesirableembolic events can be avoided without stopping the heart or otherwiseinterfering with the normal function of the circulatory system. Inaddition, selective perfusion of the arch vessels with a perfusate ofpreselected temperature or chemical composition can be performed throughthe perfusion lumen 314 of the aortic perfusion filter shunt apparatus310. The perfusate that exits the perfusion ports 316 will beconcentrated in the arch vessels by the presence of the filter meshmaterial of the expandable shunt conduit 312.

[0065] In addition, the aortic perfusion filter shunt apparatus 310 ofFIG. 17 may be combined with the aortic occlusion mechanism of FIGS.9a-9 b and 10 a-10 b or 11 a-11 b and 12 a-12 b for performing completecardiopulmonary bypass with cardioplegic arrest. With this arrangement,one catheter will provide a motionless stopped heart environment forintricate cardiac surgery while on bypass and cerebrovascular protectionby filtration an selective perfusion while on or off bypass.

[0066] Additionally or alternatively, the aortic perfusion filter shuntapparatus 310 of FIG. 17 may be operated in the alternate method of usedescribed above in connection with FIGS. 1-3 by inflating the upstreamsealing member 322 only to expand the shunt conduit 312 and leaving thedownstream sealing member 324 uninflated. The annular space around theexpandable shunt conduit 312 is perfused through the perfusion ports 316of the perfusion lumen 314. When using this alternate method, the aorticperfusion filter shunt apparatus 310 may be simplified by eliminatingthe downstream sealing member 324 from the shunt conduit 312.

[0067]FIG. 18 shows a combined aortic perfusion shunt apparatus 330 withan embolic filter mechanism 332 positioned at the downstream end of theshunt conduit. The elongated catheter shaft 336 and the expandable shuntconduit 312 of the apparatus 330 may be built according to any of thepreviously described embodiments. Attached to the apparatus 330 at thedownstream end of the expandable shunt conduit 312 is an embolic filtermechanism 332 made of a filter mesh material. The filter mesh materialof the embolic filter mechanism 332, which may be made of any of thefilter materials described above, can be chosen to capture macroembolionly or to capture macroemboli and microemboli. The embolic filtermechanism 332 may be roughly conical in shape as shown or any otherconvenient geometry. Other examples of suitable geometries andconstructions for the embolic filter mechanism 332 may be found incommonly owned, copending U.S. provisional application 60/060,117, andcorresponding U.S. patent application Ser. No. 09/158,405, which haspreviously been incorporated by reference.

[0068] When the aortic perfusion shunt apparatus 330 is deployed withinthe aortic arch, the arch vessels and thus the cerebral vasculature, areprotected from embolization or hypoperfusion by selective perfusionthrough the perfusion lumen 338 of the elongated catheter shaft 336,while the organs and tissues downstream of the apparatus 330 areprotected from embolization by the embolic filter mechanism 332. Inaddition, the aortic perfusion shunt apparatus 330 of FIG. 18 may becombined with the aortic occlusion mechanism of FIGS. 9a-9 b and 10 a-10b or 11 a-11 b and 12 a-12 b for performing complete cardiopulmonarybypass with cardioplegic arrest. Thus, one catheter will provide amotionless stopped heart environment for intricate cardiac surgery whileon bypass and cerebrovascular protection by filtration and selectiveperfusion while on or off bypass.

[0069]FIG. 19 shows an alternate embodiment of an aortic perfusion shuntapparatus 340 combined with an embolic filter mechanism 342 positionedwithin the expandable shunt conduit 344. This embodiment is similar inconstruction and materials to the combined aortic perfusion shuntapparatus and embolic filter mechanism of FIG. 16, except that theembolic filter mechanism 342 is positioned within the inner lumen 346 ofthe expandable shunt conduit 344. This arrangement provides a morecompact construction of the apparatus 340. The arrangement also providesadditional protection and support for the embolic filter mechanism 342,which can thus be made of very delicate or intricately arranged finefilter mesh material. The additional protection also provides morepositive capture of embolic materials within the embolic filtermechanism 342, particularly upon withdrawal of the device after use,because the filter mesh material of the embolic filter mechanism 342 issurrounded with the relatively impermeable material of the expandableshunt conduit 344. The apparatus of FIG. 19 can also be combined withany of the embodiments or constructions previously described inconjunction with other embodiments of the present invention, includingthe aortic occlusion mechanisms of FIGS. 9a-9 b and 10 a-10 b or 11 a-11b and 12 a-12 b. Likewise, all operable combinations and subcombinationsof the features of the present invention described herein, orincorporated by reference, are considered to be within the scope of thepresent invention whether or not they have been explicitly described.

[0070]FIGS. 20 and 21 show an aortic perfusion shunt apparatus 400configured for retrograde deployment via femoral artery access andhaving upstream and downstream sealing members 402, 404 operated byextendible and retractable elongated expansion members 406, 408. FIG. 20is a cutaway perspective view of the perfusion shunt apparatus 400deployed within the aorta. FIG. 21 shows the apparatus with theperfusion shunt conduit 410 in a collapsed state for insertion orwithdrawal of the device from the patient.

[0071] Similar to the previously described embodiments, the aorticperfusion shunt apparatus 400 has an elongated catheter or cannula shaft412 that may be configured for introduction via peripheral arteryaccess, as shown, or for central aortic access. An expandable shuntconduit 410 is mounted near the distal end of the catheter shaft 412.The expandable shunt conduit 410 is a tubular structure of either porousor impermeable fabric. An upstream elongated expansion member 406extends out of a port or ports 414 on the catheter shaft 412 andencircles the shunt conduit 410 near its upstream end 416. The fabric ofthe shunt conduit 410 is folded back over the upstream elongatedexpansion member 406 and sewn with a seam 418 to enclose the upstreamelongated expansion member 406. A downstream elongated expansion member408 extends out of another port or ports 420 on the catheter shaft 412and encircles the shunt conduit 410 near its downstream end 422. Thefabric of the shunt conduit 410 is folded back over the downstreamelongated expansion member 408 and sewn with a seam 424 to enclose thedownstream elongated expansion member 408.

[0072] The upstream elongated expansion member 406 is a flexible wire,rod, fiber or cable made from a polymer or metal, such as stainlesssteel or a nickel-titanium alloy. A first actuation member 426 extendsthrough the catheter shaft 412 and connects the upstream elongatedexpansion member 406 to a first actuator button 430 on the proximal endof the perfusion shunt apparatus 400. The first actuation member 426 maybe an extension of the upstream elongated expansion member 406 or it maybe a separate wire or rod attached to the upstream elongated expansionmember 406. Similarly, the downstream elongated expansion member 408 isa flexible wire, rod, fiber or cable made from a polymer or metal, suchas stainless steel or a nickel-titanium alloy. A second actuation member428 extends through the catheter shaft 412 and connects the downstreamelongated expansion member 408 to a second actuator button (not visiblein this view) on the proximal end of the perfusion shunt apparatus 400.The second actuation member 428 may be an extension of the downstreamelongated expansion member 408 or it may be a separate wire or rodattached to the downstream elongated expansion member 408.Alternatively, the upstream elongated expansion member 406 and thedownstream elongated expansion member 408 may be actuated by a singleactuation member 426 and actuator button 430.

[0073] To prepare the aortic perfusion shunt apparatus 400 for use, theactuator button or buttons 430 are moved proximally to retract theupstream elongated expansion member 406 and the downstream elongatedexpansion member 408 into the catheter shaft 412 through the ports 414,420. This gathers the upstream end 416 and the downstream end 422 of theshunt conduit 410 and collapses the shunt conduit 410 toward thecatheter shaft 412, as shown in FIG. 21. Optionally, an outer tube (notshown) may be placed over the collapsed shunt conduit 410.

[0074] The aortic perfusion shunt apparatus 400 is inserted andpositioned as previously described. Once the aortic perfusion shuntapparatus 400 is in the proper position, the process is reversed todeploy the expandable shunt conduit 410. The actuator button or buttons430 are moved distally to extend the upstream elongated expansion member406 and the downstream elongated expansion member 408 from the ports414, 420 in the catheter shaft 412. This expands the upstream end 416and the downstream end 422 of the shunt conduit 410 until they contactand create a seal against the inner surface of the aorta, as shown inFIG. 20. Advantageously, the shunt conduit 410 maybe made of a somewhatelastic film or fabric to easily accommodate variations in the sizes ofpatient's aortas.

[0075] As in previously described embodiments, the aortic perfusionshunt apparatus 400 of FIGS. 20 and 21 may optionally include one ormore radiopaque and/or sonoreflective markers on the apparatus forenhanced imaging by fluoroscopic or ultrasonic imaging techniques.Another feature that can be combined with each of the embodiments of thepresent invention is an aortic transillumination system for locating andmonitoring the position of the catheter, the shunt and the optionalocclusion devices without fluoroscopy by transillumination of the aorticwall. Aortic transillumination systems using optical fibers and/or lightemitting diodes or lasers suitable for this application are described incommonly owned, copending U.S. patent application Ser. No. 60/088,652,filed Jun. 9, 1998, which is hereby incorporated by reference in itsentirety. By way of example, the aortic perfusion shunt apparatus 400 ofFIGS. 20 and 21 is easily adaptable for use with a fiberoptic system foraortic transillumination. For this purpose, the upstream elongatedexpansion member 406 and the first actuation member 426 may be made of afirst optical fiber, preferably a flexible polymeric optical fiber.Similarly, the downstream elongated expansion member 408 and the secondactuation member 428 may be made of a second optical fiber, alsopreferably a flexible polymeric optical fiber. An optical coupling (notshown) would be provided at the proximal end of the perfusion shuntapparatus 400 to connect the optical fibers to a light source. Thefiberoptic upstream elongated expansion member 406 and the fiberopticdownstream elongated expansion member 408 can be made lossy by abradingthe optical fibers or their cladding so that light escapes through thewalls of the fibers. The light emitted by the fiberoptic upstreamelongated expansion member 406 and the fiberoptic downstream elongatedexpansion member 408 is visible through the aortic wall and can be usedto locate and monitor the position and the deployment state of theexpandable shunt conduit 410. Similarly, in embodiments of the perfusionshunt apparatus utilizing an aortic occlusion device, one or moreoptical fibers or other light emitting devices may be positioned on theaortic occlusion device to locate and monitor its position and state ofdeployment.

[0076] Likewise, the features and embodiments of the present inventionmay also be combined with a bumper location device for facilitatingcatheter insertion and positioning by providing tactile feedback whenthe catheter device contacts the aortic valve. Bumper location devicessuitable for this application are described in commonly owned, copendingU.S. provisional patent applications No. 60/060,158, filed Sep. 26,1997, and No. 60/073,681, filed Feb. 4, 1998, and corresponding U.S.patent application Ser. No. 09/161,207, which are hereby incorporated byreference in their entirety.

[0077] While the present invention has been described herein withrespect to the exemplary embodiments and the best mode for practicingthe invention, it will be apparent to one of ordinary skill in the artthat many modifications, improvements and subcombinations of the variousembodiments, adaptations and variations can be made to the inventionwithout departing from the spirit and scope thereof.

What is claimed is:
 1. A method of cerebral embolic protection,comprising: intercepting embolic materials in the blood flow in apatient's ascending aorta with an aortic shunt device placed in thepatient's aortic arch; and redirecting the embolic materials from thepatient's ascending aorta past the patient's aortic arch vessels to thepatient's descending aorta.
 2. The method of claim 1, furthercomprising: perfusing the patient's aortic arch vessels with a fluidwhich is free of embolic materials.
 3. The method of claim 2, furthercomprising: perfusing the patient's aortic arch vessels through aperfusion lumen in the aortic shunt device.
 4. The method of claim 3,wherein: perfusing the patient's aortic arch vessels with hypothermicoxygenated blood.
 5. The method of claim 1, wherein the aortic shuntdevice is introduced into the aorta on an elongated catheter shaft. 6.The method of claim 5, further comprising perfusing the patient's aorticarch vessels through an arch perfusion lumen in the elongated cathetershaft, the arch perfusion lumen having a fluid connection with an archperfusion port external to the aortic shunt device.
 7. The method ofclaim 6, further comprising perfusing the patient's coronary vesselsthrough a coronary perfusion lumen in the elongated catheter shaft, thecoronary perfusion lumen having a fluid connection with a coronaryperfusion port upstream of the aortic shunt device.
 8. The method ofclaim 7, further comprising perfusing the patient's corporeal vesselsthrough a corporeal perfusion lumen in the elongated catheter shaft, thecorporeal perfusion lumen having a fluid connection with a corporealperfusion port downstream of the aortic shunt device.
 9. The method ofclaim 1, further comprising occluding blood flow through the patient'saorta.
 10. The method of claim 1, wherein the body of the aortic shuntdevice has an approximately cylindrical configuration with a centralblood flow lumen.
 11. The method of claim 10, further comprisingoccluding the central blood flow lumen.
 12. The method of claim 10,further comprising creating a circumferential seal between an upstreamend of the aortic shunt device and a wall of the patient's ascendingaorta.
 13. The method of claim 12, further comprising creating acircumferential seal between a downstream end of the aortic shunt deviceand the wall of the patient's descending aorta.
 14. The method of claim1, further comprising creating a seal between an upstream end of theaortic shunt device and a wall of the patient's ascending aorta.
 15. Themethod of claim 14, further comprising creating a seal between adownstream end of the aortic shunt device and the wall of the patient'sdescending aorta.
 16. A method of cerebral embolic protection,comprising: intercepting blood flow from a patient's ascending aortawith an aortic shunt device placed in the patient's aortic arch; andredirecting the blood flow from the patient's ascending aorta and anyembolic materials contained in the blood flow past the patient's aorticarch vessels to the patient's descending aorta.
 17. The method of claim16, further comprising: perfusing the patient's aortic arch vessels witha fluid which is free of embolic materials.
 18. The method of claim 17,further comprising: perfusing the patient's aortic arch vessels througha perfusion lumen in the aortic shunt device.
 19. The method of claim18, wherein: perfusing the patient's aortic arch vessels withhypothermic oxygenated blood.
 20. The method of claim 16, wherein theaortic shunt device is introduced into the aorta on an elongatedcatheter shaft.
 21. The method of claim 20, further comprising perfusingthe patient's aortic arch vessels through an arch perfusion lumen in theelongated catheter shaft, the arch perfusion lumen having a fluidconnection with an arch perfusion port external to the aortic shuntdevice.
 22. The method of claim 21, further comprising perfusing thepatient's coronary vessels through a coronary perfusion lumen in theelongated catheter shaft, the coronary perfusion lumen having a fluidconnection with a coronary perfusion port upstream of the aortic shuntdevice.
 23. The method of claim 22, further comprising perfusing thepatient's corporeal vessels through a corporeal perfusion lumen in theelongated catheter shaft, the corporeal perfusion lumen having a fluidconnection with a corporeal perfusion port downstream of the aorticshunt device.
 24. The method of claim 16, further comprising occludingblood flow through the patient's aorta.
 25. The method of claim 16,wherein the body of the aortic shunt device has an approximatelycylindrical configuration with a central blood flow lumen.
 26. Themethod of claim 25, further comprising occluding the central blood flowlumen.
 27. The method of claim 25, further comprising creating acircumferential seal between an upstream end of the aortic shunt deviceand a wall of the patient's ascending aorta.
 28. The method of claim 27,further comprising creating a circumferential seal between a downstreamend of the aortic shunt device and the wall of the patient's descendingaorta.
 29. The method of claim 16, further comprising creating a sealbetween an upstream end of the aortic shunt device and a wall of thepatient's ascending aorta.
 30. The method of claim 29, furthercomprising creating a seal between a downstream end of the aortic shuntdevice and the wall of the patient's descending aorta.
 31. Apparatus forcerebral embolic protection, comprising: an aortic shunt deviceconfigured for placement in a patient's aortic arch, the aortic shuntdevice having an upstream end configured for intercepting embolicmaterials in the blood flow in a patient's ascending aorta, a bodyconfigured for redirecting the embolic materials past the patient'saortic arch vessels, and a downstream end configured for discharging theredirected embolic materials into the patient's descending aorta. 32.The apparatus of claim 31, wherein the body of the aortic shunt deviceis made of a material impermeable to embolic materials.
 33. Theapparatus of claim 31, wherein the body of the aortic shunt device ismade of a material impermeable to blood and embolic materials.
 34. Theapparatus of claim 31, further comprising an arch perfusion lumen in theelongated catheter shaft, the arch perfusion lumen having a fluidconnection with an arch perfusion port external to the body of theaortic shunt device.
 35. The apparatus of claim 34, further comprising acoronary perfusion lumen in the elongated catheter shaft, the coronaryperfusion lumen having a fluid connection with a coronary perfusion portupstream of the aortic shunt device.
 36. The apparatus of claim 35,further comprising a corporeal perfusion lumen in the elongated cathetershaft, the corporeal perfusion lumen having a fluid connection with acorporeal perfusion port downstream of the aortic shunt device.
 37. Theapparatus of claim 31, further comprising a means for occluding bloodflow through the aorta.
 38. The apparatus of claim 31, wherein the bodyof the aortic shunt device has an approximately cylindricalconfiguration with a central blood flow lumen.
 39. The apparatus ofclaim 38, further comprising a means for occluding the central bloodflow lumen.
 40. The apparatus of claim 39, wherein the upstream end ofthe aortic shunt device is configured to create a circumferential sealwith a wall of the patient's ascending aorta.
 41. The apparatus of claim40, wherein the downstream end of the aortic shunt device is configuredto create a circumferential seal with the wall of the patient'sdescending aorta.
 42. The apparatus of claim 31, wherein the upstreamend of the aortic shunt device is configured to create a seal with thepatient's ascending aorta.
 43. The apparatus of claim 42, wherein thedownstream end of the aortic shunt device is configured to create a sealwith the patient's descending aorta.
 44. Apparatus for cerebral embolicprotection, comprising: an aortic shunt device configured for placementin a patient's aortic arch, the aortic shunt device having an upstreamend configured for intercepting blood flow from the patient's ascendingaorta, a body configured for redirecting the blood flow from thepatient's ascending aorta and any potential embolic materials containedin the blood flow past the patient's aortic arch vessels, and adownstream end configured for discharging the redirected blood flow intothe patient's descending aorta.
 45. The apparatus of claim 44, whereinthe body of the aortic shunt device is made of a material impermeable toembolic materials.
 46. The apparatus of claim 44, wherein the body ofthe aortic shunt device is made of a material impermeable to blood andembolic materials.
 47. The apparatus of claim 44, further comprising anarch perfusion lumen in the elongated catheter shaft, the arch perfusionlumen having a fluid connection with an arch perfusion port external tothe body of the aortic shunt device.
 48. The apparatus of claim 47,further comprising a coronary perfusion lumen in the elongated cathetershaft, the coronary perfusion lumen having a fluid connection with acoronary perfusion port upstream of the aortic shunt device.
 49. Theapparatus of claim 48, further comprising a corporeal perfusion lumen inthe elongated catheter shaft, the corporeal perfusion lumen having afluid connection with a corporeal perfusion port downstream of theaortic shunt device.
 50. The apparatus of claim 44, further comprising ameans for occluding blood flow through the aorta.
 51. The apparatus ofclaim 44, wherein the body of the aortic shunt device has anapproximately cylindrical configuration with a central blood flow lumen.52. The apparatus of claim 51, further comprising a means for occludingthe central blood flow lumen.
 53. The apparatus of claim 51, wherein theupstream end of the aortic shunt device is configured to create acircumferential seal with a wall of the patient's ascending aorta. 54.The apparatus of claim 53, wherein the downstream end of the aorticshunt device is configured to create a circumferential seal with thewall of the patient's descending aorta.
 55. The apparatus of claim 44,wherein the upstream end of the aortic shunt device is configured tocreate a seal with the patient's ascending aorta.
 56. The apparatus ofclaim 55, wherein the downstream end of the aortic shunt device isconfigured to create a seal with the patient's descending aorta.